JPH01306834A - Diazo copying material - Google Patents

Abstract

PURPOSE:To obviate difference in photosensitivity between top and rear surfaces so as to refrain from superimpose of image even in case of applying both sides copying to the copying material by mounting a diazo photosensitive layer on the rear surface of a supporting body through a precoat layer and directly mounting the diazo photosensitive layer on the top surface of the supporting body, respectively. CONSTITUTION:The diazo photosensitive layer is mounted on the rear surface of the supporting body through the precoat layer and directly on the top surface of the supporting body, respectively. Accordingly, the sensitivity of a copy image and a formation on the rear surface are increased to almost the same degree as that of the top surface of the material. And, at the time of copying the both sides of the material, UV rays used for exposure do not transmit to the diazo photosensitive layer existing on the opposite side of the precoat layer by the presence of the precoat layer. Thus, the superimpose of the copy images existing on the top and back surfaces respectively is prevented, and the difference in the sensitivity of the photosensitive layers between the top and the rear surface of the copying material is obviated.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a diazo copying material capable of copying on both the front and back sides.

[Conventional technology]

Conventionally, diazo copying materials capable of copying on both the front and back sides have been commercially available in which diazo photosensitive layers are provided directly on both the front and back sides of the support, but the copy density on the back side of the support is inevitably low. However, when double-sided copying is performed, part of the ultraviolet rays passes through the support during exposure, so the copied images on the front and back sides overlap each other. However, the problem was that the images lacked sharpness.

[Problem to be solved by the invention]

The present invention differs from the above-mentioned conventional products in that there is no difference in photosensitive characteristics between the photosensitive layers on the front side and the back side, and when double-sided copying is performed, there is no overlap between the copied images on the front side and the back side, resulting in clear copies. The object is to provide a diazo copying material that provides images.

[Means to accomplish the task]

According to the studies of the present inventors, it has been found that the above object can be achieved by providing a diazo photosensitive layer directly on the front side of the support and providing the diazo photosensitive layer on the back side of the support via a precoat layer. It was done.

That is, the diazo copying material of the present invention is characterized in that a diazo photosensitive layer is provided directly on the front surface of the support, and a diazo photosensitive layer is provided on the back surface of the support via a precoat layer.

In the diazo copying material according to the present invention, the diazo photosensitive layer on the back side is provided on the support via the precoat layer. Furthermore, when double-sided copying is performed, the exposed ultraviolet rays do not pass through to the diazo photosensitive layer on the opposite side due to the presence of the precoat layer, thereby preventing overlapping of the copied images on both the front and back sides. I can do it.

Diazo copying materials in which a diazo photosensitive layer is provided on the front surface of the support through a precoat layer and a diazo photosensitive layer is provided directly on the back surface improve the overlapping of copied images due to UV transmission during exposure, but the overlap between the front and back sides is improved. This is not preferable because it causes a significant difference in copy quality, etc.

On the other hand, if a diazo photosensitive layer is provided on both sides via a precoat layer, 4N coating is required for both the front and back sides.
For this reason, it is necessary to apply two coats using the coating machine generally used for coating diazo copying materials, or to use new coating equipment, which has the disadvantage of being significantly disadvantageous in terms of cost. It's not appropriate.

In other words, the diazo copying material of the present invention not only has excellent quality but also 'f! Since commonly used coating equipment can be used as is for five-sided surfaces, its practical value is extremely high.

As the diazo compound and coupling component used in the photosensitive layer of the present invention, those conventionally used can be used as they are.

That is, as a diazo compound, for example, 4-diazo-1
-dimethylaminobenzene, 4-diazo-1-diethylaminobenzene, 4-diazo-1-dipropylaminobenzene, 4-diazo-1-methylbenzylaminobenzene, 4-diazo-1-dibenzylaminobenzene, 4-
diazo-1-ethylhydroxyethylaminobenzene,
4-Diazo-1-diethylamino-3-methoxybenzene, 4-diazo-1-dimethylamino-2-methylbenzene, 4-diazo-1-benzoylamino-2゜5-jethoxybenzene, 4-diazo-1- Morpholinobenzene, 4-diazo-1-morpholino-2,5-jethoxybenzene, 4-diazo-1-morpholino-2,5-dibutoxybenzene, 4-diazo-1-anilinobenzene,
4-Diazo-1-dimerixylamino-3-carboxybenzene, 4-diazo-1-tolylmercapto-2,5-
Metal halides (e.g. zinc chloride,
Examples include double salts with cadmium chloride, tin chloride, etc.), and salts of the diazo compounds with strong acids such as sulfuric acid, boron tetrafluoride, hexafluorophosphoric acid, etc., but are not limited to these, of course. do not have.

Examples of couplers include resorcinol, phloroglucin, 2,5-dimethyl-4-morpholinomethylphenol, 3-hydroxycyanoacetanilide, parasulfoacetanilide, 1-benzoylamino-8-hydroxynaphthalene-3,6-disulfonamide, 2 ,2-
Dihydroxynaphthalene, sodium 2,7-dihydroquinonaphthalene-3,6-disulfonate, sodium 2,5-dihydroxynaphthalene-6-sulfonate.

Sodium 1-hydroxynaphthalene-4-sulfonate, 1
-Amino-3-hydroxynaphthalene-3,6-disulfonamide, naphthol AS, naphthol AS-D, 2
-Hydroxynaphthalene-3-biguanide, 2-hydroxynaphthoic acid morpholinopropylamide, 2-hydroxynaphthoic acid ethanolamide, 2-hydroxynaphthoic acid-N-dimethylaminopropylamide hydrochloride,
2,4.2',4'-tetrahydroxydiphenyl,
Examples include 2,4.2', 4'-tetrahydroxydiphenyl sulfoxide, but especially 2-hydroxy-3
- The use of naphthoic couplers is preferred.

In the present invention, in addition to the above-mentioned materials, various auxiliary additive components commonly used in diazo copying materials can be used. Examples of such substances include 1, for example, as a development accelerator, ethylene glycol, triethylene glycol, and various thermofusible substances such as waxes, higher fatty acids and their derivatives; as a storage improver, naphthalene monosulfone; sodium acid, sodium naphthalene disulfonate, sodium naphthalene trisulfonate,
Sulfosalicylic acid, cadmium sulfate, magnesium sulfate, cadmium chloride, zinc chloride, etc.; As antioxidants, urea compounds and thiourea compounds; As dissolution aids,
Caffeine, thiopherin, etc.; As acid stabilizers, citric acid, tartaric acid, sulfuric acid, oxalic acid, boric acid, phosphoric acid, pyrophosphoric acid, etc.; As alkali generators, urea, thiourea, ammonium salts of organic or inorganic acids, etc.; Images As a concentration enhancer,
Talc, kaolin, silica, starch, clay, calcium carbonate, magnesium hydroxide, styrene resin particles,
Examples include organic and inorganic fine particles such as urea-formalin condensate resin fine particles. Furthermore, in the present invention,
If necessary, a small amount of saponin may also be added. Further, in order to strongly bind the diazo compound, coupler, and various auxiliary additive components onto the precoat layer, a binder is applied as necessary, and examples of the binder include polyvinyl alcohol, methyl cellulose, polymethacrylic acid ester, Conventional types such as solution type and emulsion type containing polymers such as polyacrylic acid ester, polyvinyl acetate, polystyrene, and polyurethane are applicable.

Further, as the material for forming the precoat layer, conventionally known materials can be used as they are, but preferably a material prepared by dissolving an image density improver or an ultraviolet fastening agent in a binder is used.

In this case, inorganic or organic fine particles such as fine silica powder, starch, clay, fine alumina powder, calcium carbonate, resin, etc. can be used as the image density improver and the ultraviolet fast speeding agent.

The binder may also be a conventional resin, for example.

Polyvinyl alcohol, polyacrylamide, casein, gelatin, starch and its derivatives, polyvinylpyrrolidone, carboxymethylcellulose, methylcellulose, ethylcellulose, chlorinated rubber, polystyrene (IW)
:100,000 or more), polyurethane, urea-formalin resin, phenol resin, polyvinyl acetate, polyvinyl chloride,
Vinyl chloride/acrylic ester copolymer, vinyl chloride/vinyl acetate copolymer, polystyrene, polyester,
Examples include styrene/butadiene/acrylic copolymers, polyacrylic esters, polyacrylamide, polymethacrylic esters, and polybutadiene.

Further, the precoat layer may contain an ultraviolet absorber, wax, etc. in addition to the above-mentioned compounds, if necessary.

To produce the diazo copying material of the present invention, first, a coating solution in which the diazo compound, coupler, and other auxiliary additive components are dissolved or dispersed is coated on the surface of a support such as paper, synthetic paper, or plastic film using a conventional method. Apply and dry. Next, a coating solution in which an image density improver such as silica and a binder are dissolved or dispersed is provided as a precoat layer on the back side of the support, and then a coating solution containing a diazo compound, a coupler, and other auxiliary components is coated in a conventional manner. It can be applied and dried according to the method.

〔Effect of the invention〕

The diazo copying material of the present invention has a diazo photosensitive layer on the back side of the support via a precoat layer and a diazo photosensitive layer directly on the front side of the support, so unlike conventional products, the photosensitive characteristics of both the front and back sides are different. There is no difference, and even when double-sided copying is performed, clear images with no overlap can be obtained between the copied images on both the front and back sides.

〔Example〕

Hereinafter, the present invention will be explained in more detail with reference to Examples.

Example silica fine particles (average particle size 3μ) 3g
water
A coating solution of 100 g was coated on the back side of a base paper for diazo copying paper and dried to form a precoat layer of 1.5 g/I.

Furthermore, citric acid 2g zinc chloride 5g thiourea
5g triethylene glycol 5g water
A coating solution of 100 g was applied and dried to form an Iglof photosensitive layer.

On the other hand, the surface of this diazo copying base paper contains citric acid.
2g zinc chloride
5g thiourea
5g triethylene glycol
5g silica fine particles (average particle size 0.1μ)
2g water
A coating solution of 100 g was applied and dried to form an Ig/rrl photosensitive layer, and a diazo copying material (
Sample A) was obtained.

Comparative Example The coating liquid applied to the front side of the diazo copying base paper in the above example was applied to the front and back sides of the diazo copying base paper and dried to form an Ig/rrr photosensitive layer. (Sample B) was obtained.

Using a dry diazo copying machine (5M-1500 manufactured by Ricoh), each of the samples obtained as described above was stacked with an appropriate original image, exposed on the front side and the back side, and then developed. Then, the image density was measured using a photovolt densitometer. Copy uniformity and copy conditions on the front and back sides were also evaluated. The results are shown in Table-1.

Table-1

Claims (1)

[Claims] (1) A diazo copying material characterized in that a diazo photosensitive layer is provided directly on the surface of the support and a diazo photosensitive layer is provided on the back surface of the support via a precoat layer.